Hornady TAP 9mm 147vs 127 vs 147

picked up some 147s figuring that bigger is better. anyone have any input?

115 vs 127 vs 147

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Normally, groups spread as the round gets heavier. More KD power though. Life is full of tradeoffs.

KD power?

Knock down

I usually carry the heaviest weight bullet in whatever caliber I am carrying. The one exception being .357mag due to the very well known stopping ability of the 125gr load through history and I carry a snubbie and want it to get as much velocity as possible.

The reason I go with the heaviest weight is that the heavier the weight the more the bullet will carry momentum into its target and penetrate deeper. Not really sure about the loss of accuracy because I have never tested that one but it seems like that may change depending on the caliber in question. I have a firm belief that any caliber from 9mm up will stop what you are shooting at(large game animals not included) assuming you can accurately hit the target where/when you need to. Thus practice as much as you can afford.

here is the FBI Report every gun owner should read......

Hiredgun30 said:

here is the FBI Report every gun owner should read......

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Very informative. Supports what I have said all along, proper shot placement and grouping are far more important.

Correct Information

i have looked over this thread and read alot of good info, but also alot of misguided info. first let me start off by saying that to the original question if you are looking for a 9mm with the most knockdown power for defense go with the 124 grain. now i realize most of you think im an idiot. hear me out. when looking at a defense round you want knockdown power. now i read someone on here mention bigger bullet=deeper penetration=better, that is wrong. knockdown power the transfer of kenetic energy from the bullet to the target, a bullet that penetrates deeper, heavier grains, hold on to the energy longer equaling less knockdown power. i mentioned knock down power is the transfer of kenetic energy. obiously the more kenetic energy the bullet has means the more knockdown it has. many will tell you this automatically means get the heavier 147 grain. again WRONG. between calibers heavier/bigger is better, for instance a 147 grain 9mm Hornady TAP with a velocity of 975 FPS has 310 ft/lbs of kinetic energy, a 230 grain .45 acp hornady TAP with a velocity of 950 FPS has 460 ft/lbs of kenetic enrgy, between calibers, bigger/heavier is better. within one caliber it is the opposite. proof= a 147 grain 9mm hornady TAP with a velocity of 975 FPS has 310 ft/lbs of kinetic energy, a 124 grain 9mm hornady TAP with a velocity of 1110 FPS has 339 ft/lbs of kinetic energy. also the lighter grain will dump more of its energy faster within the target. and when looking for knockdown you want higher kenetic energy with more energy dump/transfer. i hope this information has helped to correct some of the misinformed ideas and helped you make a decision for what you want. again i would say go with the lighter wieght 124 grain, you WILL get MORE knockdown, its all in the numbers

"a gun is just a chunk of steel, only when it is combined with intelligence does it become a weapon"

marine 06 said:

i have looked over this thread and read alot of good info, but also alot of misguided info. first let me start off by saying that to the original question if you are looking for a 9mm with the most knockdown power for defense go with the 124 grain. now i realize most of you think im an idiot. hear me out. when looking at a defense round you want knockdown power. now i read someone on here mention bigger bullet=deeper penetration=better, that is wrong. knockdown power the transfer of kenetic energy from the bullet to the target, a bullet that penetrates deeper, heavier grains, hold on to the energy longer equaling less knockdown power. i mentioned knock down power is the transfer of kenetic energy. obiously the more kenetic energy the bullet has means the more knockdown it has. many will tell you this automatically means get the heavier 147 grain. again WRONG. between calibers heavier/bigger is better, for instance a 147 grain 9mm Hornady TAP with a velocity of 975 FPS has 310 ft/lbs of kinetic energy, a 230 grain .45 acp hornady TAP with a velocity of 950 FPS has 460 ft/lbs of kenetic enrgy, between calibers, bigger/heavier is better. within one caliber it is the opposite. proof= a 147 grain 9mm hornady TAP with a velocity of 975 FPS has 310 ft/lbs of kinetic energy, a 124 grain 9mm hornady TAP with a velocity of 1110 FPS has 339 ft/lbs of kinetic energy. also the lighter grain will dump more of its energy faster within the target. and when looking for knockdown you want higher kenetic energy with more energy dump/transfer. i hope this information has helped to correct some of the misinformed ideas and helped you make a decision for what you want. again i would say go with the lighter wieght 124 grain, you WILL get MORE knockdown, its all in the numbers

"a gun is just a chunk of steel, only when it is combined with intelligence does it become a weapon"

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"Knock down power" is substantially less that a scientific term. If I were to embrace such a layman's description, I would have to opt for ESP (effective stopping power). The target is most effective stopped when it cannot continue with the fight. This is either achieved with interruption of the CNS (central nervous system) or hydraulic bleed down - one being more obviously effective, but more difficult to obtain.

W/o going into too much detail why I find your analysis less that accurate, it does leave out the consideration of expansion (frontal area v pounds/sq. ft.) not as it relates to knock down power (transfer of kinetic energy), but rather to ESP via disruption of CNS or hydraulic bleed down.

My personal choice is Federal .45 ACP HST in 185 or 230 grain out of 4.25" or 5" barrel.

Hornady TAP ammo was designed to fragment. Gold Dot is a great expansion round, but IMO nothing beats HST for expansion, weight retention; hence superior stopping power.
http://archery.ar15.com/archive/topic.html?b=5&f=20&t=65023

http://www.btfh.net/shoot/bullet-test-2.html

http://www.btfh.net/shoot/bullet-test-3.html

http://www.btfh.net/shoot/bullet-test-6.html

http://www.btfh.net/shoot/bullet-test-7.html

Put the bullet where it is supposed to go and stop worrying. As long as the cartridge functions properly, and the bullet makes it to the intended target, odds are the BG is going to stop, if BG does not stop keep shooting. IMO practice is much more important the bullet weight, or bore size. Get away from the FBI targets and learn to point shoot, at moving small targets. I use water balloons swinging from tree limbs at head level, with a airsoft gun. For revolvers I use wax bullets in special cartridges made for 209 primers. Start with stationary balloons, then work your way up to swinging the balloons. These are good exercises for relieving stress, shooting when stressed will increase your likelihood to function in a real fight. If you can hit a swinging balloon, you can hit a head.

marine 06 said:

when looking at a defense round you want knockdown power. now i read someone on here mention bigger bullet=deeper penetration=better, that is wrong. knockdown power the transfer of kenetic energy from the bullet to the target, a bullet that penetrates deeper, heavier grains, hold on to the energy longer equaling less knockdown power

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Just to clarify I said heavier bullet=deeper penetration and I don't recall ever mentioning knock down because in my opinion it is a mostly irrelevant term. Personally I don't give a crap about KD power as someone else already stated you stop an attacker by cns disruption or blood loss now both of those require you to hit vital areas in the human body. Which requires very accurate fire which is what someone else pointed too and I completely agree with. Off topic but worth mentioning shooting balloons is awesome but I always practice with what I carry, the 209 primer thing sounds interesting tho.

So now I think we can all agree that it takes accurate fire to hit a vital area. Some of those vital areas are deep in the body and depending on the angle the person is standing can be as much as 18 inches on a bigger person. Which is why I carry the heaviest bullet in whatever said caliber unless there is historical evidence pointing to a light round being better. So far I have found two the 125 grain .357 mag I mentioned in the earlier post and the 124 grain 9mm both tend to do better than there heavier and slower brothers. I want to give myself the best possible chance of hitting a vital blood vessel or nerve so I want that bullet to go as far into the attacker as possible to maximize my chances. I am completely ok with it holding on to its energy as long as it wants so long as it goes deep enough to hit something vital or according to a few studies(looking for citations I will add when found) goes all the way thru the attacker thus making more escape routes for blood and quickening blood loss and ending the engagement faster. So that is why I go with heaver bullets.

Sorry that ended up being longer than I wanted and I would also like to state that I am not saying your wrong just clarifying my opinion because you took what I said about penetration and added KD power to it. Thus stating that I was wrong but only after you added something else to the equation I never mentioned.

I believe that what marine 06 was talking about would be call kinetic transfer. It is the scientific describing what we call knock down power. It is the measure of kinetic energy transferred from say a bullet to say a torso. While cavitation does cause serious damage, it is KT (kinetic transfer) that will give you the final answer on fatality in most cases. Remember, a bullet that passes through the target is just wasting energy.

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chances are that ill never need to use it. if a guy can take down an attacking bear with a 22 (very lucky) i think a 9mm or 380 in any grain will do fine for self defense. thanks for the response to all

jugglzo said:

chances are that ill never need to use it. if a guy can take down an attacking bear with a 22 (very lucky) i think a 9mm or 380 in any grain will do fine for self defense. thanks for the response to all

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I agree, use whatever you're comfortable with. But I highly recommend that you invest $20 or so into some good hollowpoints for your carry piece. They are much more effective.

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DamonK said:

I agree, use whatever you're comfortable with. But I highly recommend that you invest $20 or so into some good hollowpoints for your carry piece. They are much more effective.

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I have heard several supposedly experts argue against hollow points for .380 and below. Expansion is no good if it only travels a few inches, and then there is the time of year. I don't carry my 9X18 in cold weather, if I do it is with FMJ. My concern with self defense ammo is it hitting an innocent. In my Star 9 mm Largo I use only hollow points, in alloy framed guns hollow points can damage the feed ramp. I am looking for 12 inches of penetration from any round, if a hollow point cannot do that I stick to FMJ, or soft point ammo. I use pure lead in my 38 spl, they flatten out nicely and penetrate.

WalkingWolf said:

I have heard several supposedly experts argue against hollow points for .380 and below. Expansion is no good if it only travels a few inches, and then there is the time of year. I don't carry my 9X18 in cold weather, if I do it is with FMJ. My concern with self defense ammo is it hitting an innocent. In my Star 9 mm Largo I use only hollow points, in alloy framed guns hollow points can damage the feed ramp. I am looking for 12 inches of penetration from any round, if a hollow point cannot do that I stick to FMJ, or soft point ammo. I use pure lead in my 38 spl, they flatten out nicely and penetrate.

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Ok, why do you need 12 inches of penetration? Just how thick is this guy that you want to stop? If he's not a foot thick, you have just lost atleast a third of your energy transfer. That is what stops the bad guys. I'd rather have 6 inches of penetration than 18. Overpenetration is a huge loss of KT.

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DamonK said:

Ok, why do you need 12 inches of penetration? Just how thick is this guy that you want to stop? If he's not a foot thick, you have just lost atleast a third of your energy transfer. That is what stops the bad guys. I'd rather have 6 inches of penetration than 18. Overpenetration is a huge loss of KT.

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How would you know how much energy is lost? Wouldn't be different with each specific case? As far as what stops the bad guys, that depends on the bad guy. Bullets perform differently in real life then they do in a lab.

A foot of penetration is about average for a adult male without exiting. Most tests have been done in gelatin which really does not come close to real tissue. A foot in gelatin is probably much less in human tissue. I want a bullet to penetrate as far as possible without exiting or having little energy if it does. I don't know how much you know about the .380 but it does not have a whole lot of "KT", I am concerned more with stopping the threat than KT theories. I don't need the biggest baddest hottest most expensive round to get the job done. I don't need the most fancy expensive gun either, all I care about is stopping the threat. And on a .380 IMO I would rather use FMJ, if you don't like it too bad. You get to use whatever you want to use. I have used a 9X18 on a large charging pit bull, he stopped with one shot, not dead but stopped. The following shot to the head put him out of his misery. That is one shot of FMJ without exiting stopped the threat, goodenuf for me, YMMV.

DamonK said:

Ok, why do you need 12 inches of penetration? Just how thick is this guy that you want to stop? If he's not a foot thick, you have just lost atleast a third of your energy transfer. That is what stops the bad guys. I'd rather have 6 inches of penetration than 18. Overpenetration is a huge loss of KT.

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When more than 1/3 of U.S. adults are obese, it's a lot more likely than you'd think. I'm 6'3" and weigh about 160 pounds, not heavy by any standard. My abdomen is over 6" from front to back. Your also assuming that an attacker is directly facing you, allowing for a straight head on bullet trajectory and not standing at any sort of an angle with his side facing you, or above/below you elevation wise. I would definitely agree that over penetration is not a good thing, but you have to balance it out is what I'm trying to say.

Sangre said:

When more than 1/3 of U.S. adults are obese, it's a lot more likely than you'd think. I'm 6'3" and weigh about 160 pounds, not heavy by any standard. My abdomen is over 6" from front to back. Your also assuming that an attacker is directly facing you, allowing for a straight head on bullet trajectory and not standing at any sort of an angle with his side facing you, or above/below you elevation wise. I would definitely agree that over penetration is not a good thing, but you have to balance it out is what I'm trying to say.

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I think the figure is higher than 1/3, but your point is similar to mine. A 380 IF it over-penetrates is not going far and with very little energy. Now 7.62 Tok will penetrate level 2 body armor, it is likely to go through and have enough energy to damage anything else it touches. I would not use a FMJ in a 357, but I don't need fancy terms or studies to tell me that, just common sense. If KT is so important maybe a S&W 500 is the only ammo that should be considered, or have a handgun built for .50 BMG.

Again the most important factor is stopping the threat, and bullet placement is the most important factor in stopping the threat. A 22 long rifle can effectively stop the threat with very good accuracy. The rest is all yada yada yada.